Cork sifter



J. D. ELDER Jan. 2, 1934.

CORK S IFTER Filed May 6, 1929 4 Sheets-Sheet l INVENTOR Q-z ATTORNEY.

4 Sheets-Sheet 2 J. D. ELDER CORK SIFTER Filed May 6. 1929 ATTORNEY.

INVENTOR Jan. 2, 1934.

M@ .i ZM

Blf..

J. D. ELDER CORK S I FTER Jan. 2, 1934.

4 sheets-shea Filed May 6. 1929 ATTORNEY Jan. 2, 1934.` 1' D. ELDER 1,941,883

CORK SIFTER v Filed May 6, 1929 4 Sheets-Sheff(l 4 MLN 2a@ INVENTOR MQW 'ATTORNEY- Cil u tia, either' static or moving.

Patented Jan. 2, 1934 NETE VSTATIE'JS PATE-Nr F icE ApplicationfMay 6, 1929. Serial No.v 360,670

9 Claims.

My invention relates to cork sifters, and-more particularly to a mechanism Which may be effectively utilized for the separation of cork granules or particles varying in dimensiomand the delivery of the granules or particles'of different sizes to independent collectionrpoints.

Cork particles, both becausevof their size-and because of the loW speciiicrgravity of cork Wood, during asifting operation develop very little iner- As a consequence, it is essential, in such sifters, to impart high speed to the screens with a short quick change ofdirection in the movements thereof, in order to ensure the necessary violent agitation and movement of the cork particles to effectively-separate the smaller particles from the mass delivered to the screen. The high speed at Which the screensare required to be operated, not only tends towards a severe racking oi these screens, but alossfof' efficiency in the event of the development of looseness in the frame of the screens.

With the above conditions in mind, I haveprovided a cork sitter which is so'constructed -as Yto permit the actuation of the screens at high speeds, such screens being so supported and controlled in their movements as to relieve them from stresses which would tend to rack the frames of the screens. This permits the screens to be made oi' light material and still have them possess suilicient strength to withstand the severe Wear to which they are necessarily subjected with afprolonged u se of the structure.

In addition to the structural characteristics above referred to, a cork sifter embodying myinvention is so constructed that the cork particles upon the screen Will be subjected to a Ycontinuing Violent agitation which, by reason of the structure oi the screens, will cause the bulk of the matter delivered thereto, to travel the entire length of the screen, and be delivered to one receptacle, and the matter progressively rejected as a result of the screening operation, to be delivered to a separate receptacle.

A sitter embodying the invention is particularly adaptable to the grading of granular cork for use in the production of compositioncork. In the production of such cork, it isdesirable, in the interests of'uniformity in theproduct, that the cork granules used, be ofl graded sizes, and that the volume of the granules or" each size be fairly accurately proportioned in a -batch of the cork vcomposition, in order to secure a highly resilient product free from voids.

The granulation of cork results ina variable I product ranging from fairly llarge particles of (olf 20s-:366)

' 60 The dust and grit are valueless in the Vproductionof composition cork, and some ofthe smaller granules must be used sparingly.

In a sitter embodying my invention, awsuccession of superimposed screen units operated from the same lsource of power may be eiectively used. These various units are so constructed thatl the particles rejected by theY screen-of one unit will be delivered to the screen immediately below; in a manner to progressively remove from themass of granular cork delivered to the sifter, theusable cork granules. graded to size, the various gradings being substantially free from dust, grit andV smallerparticles of the granular cork. The usable cork may thus be -segregated'lfrom the dust and-grit, which are not usable, the latter being automatically discharged' byvthe Ymachine.

The various-screen units are4 each supported by strong rigid thrust members closely adjacent the actuating mechanism for the unit, these members being so constructed as to effectively bracethe screen'about the corners thereof, thus avoiding racking of the frame oifthescreenas a result ofv the thrust' thereon by thev actuating means.

The v' actuating means itself is sofconstructed and'arranged that the Imovement'Y of the-screen results fentirely from a properly timed movement of" the different thrust membersuag'ainst the frame, therebeing no pulling action-upon this frame. v"Ifhe manner ofA actuating the-'screen` is such that the frame is subjected to theminimum of stress from theactuating means, thus permittingl the structure of the screens to be light, it being possible to make these frames of Wood. Theuse of a screen unit having very little `4Weight permits" the operation of a multiple unit sifter at high speeds with low power.

The escape of-V dust about the sifter is not great,

but lthe-'construction of the actuating'means is such as not to be interfered with, in the event of -the'settling` of dust thereon.

Preferably, the collection receptacles consist ofordinary bags,-which form no partof the'in ventiongfthe -sifter being provided-With ducts communicating vWith the orftake chutes of the various sCreen'units'and provided -with a'distendingmember adjacent the outlets thereof aboutvvhich the bags maybe connected.

The invention consists primarily in a cork sifter embodying therein a plurality of superimposed units, each embodying a frame, having therein a screen, an imperforate bottom plate beneath said screen and spaced therefrom, and discharge means communicating respectively with the space above said screen and above said imperforate bottom plate the discharge means communicating with the space above said imperforate bottom plate delivering the screened material to the unit below, a plurality of thrust members operatively engaging diametrically opposite corners of each of said frames, supporting means for said frames carried by said thrust members respectively, a fixed bracket adjacent each of said thrust members, co-operating bearings carried by said thrust members and said brackets respectively, a rotatable member mounted upon each of said brackets, operative connections between said rotatable member and the thrust member associated therewith, and means common to the rotatable members associated with each unit for imparting similar, simultaneous movement thereto; and in such other novel features of construction and combination of parts, as are hereinafter set forth and described, and more particularly pointed out in the claims hereto appended.

Referring to the drawings,

Fig. 1 is a front elevation of a cork sifter embodying the invention, with portions of the main frame broken away;

Fig. 2 is a side view thereof with portions of the main frame broken away;

Fig. 3 is a plan view thereof with portions of the feed hopper, the mesh of the uppermost screen and a portion of the top frame broken away;

Fig. 4 is an enlarged detail View, partly in elevation and partly in section, or" one of the elements in the actuating mechanism;

Fig. 5 is a plan view thereof;

Fig. 6 is a plan View of one of the screen units;

Fig. 7 is an enlarged sectional view of said unit; and

Fig. 8 is an enlarged sectional view on the line 7--7 of Fig. 6. i

Like numerals refer to like parts throughout the several views.

1n the embodiment of the invention shown in the drawings, the structure is such as to be particularly adapted for the screening and grading of granular cork. The structure'therein shown embodies a main frame 10, having mounted there- ,in a plurality of superimposed screen units 11, 12,

curing the desired movements of the screen unit.

will rst describe one of the screen units in detail, and then explain the mechanisms for imparting movement to this screen unit and to the various other screen units.

Referring more particularly to the screen unit 11, which is of the same construction as the units 12, 13, 14 and 15, it consists of a wooden frame having side bars 16 and 17, a front bar 18 and a back bar 19, these various bars all being of wood, suitably glued or otherwise secured together.

The side bars 16 and 17 are each provided with a cleat 20, and the back bar 19 with a cleat 21, for supporting a frame 22 carrying a wire mesh 23 of the desired gauge. The gauge of the mesh 23 will vary with the character of the material to be screened or graded.

The cleats 20 extend upon an incline from adjacent the front bar 18 to adjacent the back bar 19 so as to pitch the screen 23 toward said front bar, which has an outlet opening 24 extending therethrough.

Also secured to theA side and iront bars of the screen unit, is an imperforate bottom plate 25, positioned below the screen mesh 23, but pitched in the reverse direction to said mesh. This plate 25 is preferably of sheet metal having a turned edge, by means of which it may be tted and secured to the bars 16, 17 and 18.

The plate 25 is unconnected with, and spaced away from, the back bar 19, affording space for a rectangular collecting and delivering hopper 26, the discharge nozzle 27 of which is of less length than the width of the screen frame so as to be positioned well away from the corners of said frame. The reason for this is that the actuating power for imparting movement to the screen unit is applied at the corners, and clearance is required about the corners for permitting the assembly of the thrust members in relation to the frame, and the movements of said members and said frame in relation to the parts co-operating with said members.

Cutout sections of the back and side bars are shown at 23 and 29 in Fig. 7, and cutout portions of the front and side bars are shown at 30 in said 110 Fig. 7.

The location of the hopper 26 is closely adjacent the point of delivery of the granular or other material to the screen 23, at which point the volume of material rejected by the screen will be the greatest. This will appear more fully hereinafter.

The frame or the screen unit is of progressively. increasing depth from adjacent the front bar 18 to adjacent the back bar 19, so as to aiord 12g adequate capacity above the mesh 23 and between this mesh and the bottom plate 25.

The hopper 26 has side walls 31 and 32 and a rear wall 33 adjacent the bar 19 which converge toward the discharge nozzle 27, the side of the hopper towards the front bar 18 being open, except for side wings 34 closing the gap between the converging side walls 31 and 32 and the side bars 15 and 16. By this construction, the bottom plate 25 discharges directly into the discharge nozzle 27.

Suitable corner fillets may be used where required to strengthen the screen unit at the corners.

Leading from the opening 24 through the front 135 bar 18, is a closed chute 35 having converging end walls 35a and 35D and the movable section of a discharge conduit 36 leading from the bottom of this chute.

The chute extends downwardly at am angle 14g so as to ensure a rapid conveyance of the particles from above the screen, the bottom of the opening 24 being substantially flush with the top of the screen. The degree of angularity of the end walls 35a-3b of the chutes of the different 145 units varies in order to differently locate the discharge conduits 36 and thus permit the more convenient locating of the collection receptacles, the bags 37.

The movable portions 36a of the conduits 36 150,

are connected with the xedvsections `of* said conduits by a exible conduit section 38, sofas to confine the particles flowing from the one conduit section tothe other and yet permit the free movement of the screen units during the sifting operation. Each of the conduits 36 is provided adjacent its outlet with an enlarged headv 39, about which the tops of the bags may be partially closed, these enlarged heads serving to distend the tops of the bags so as to avoid possible clogging of the chutes toward the mouths of said bags.

By making the ducts of a plurality of sections 36-36a, one of each of which sections is fixed, and the other of which is movable with a screen unit, the difficulties of collecting the graded Ymatter is obviated and the free movement of each sifter unit is permitted. The flexible connectingsections 38 are desirable, since it prevents the possibility of draughts picking up the small, light particles of cork and blowing them about the room. Other means for securing this result, however, may be employed.

All of the parts of the screen unit heretofore described are of wood, excepting the mesh 23,

the bottom plate 25, the hopper 26 and its outlet 27, and the chutes and the movable portion of the conduit 36, which are of metal.

Operative upon each corner of the screen frame is a thrust member having the two-fold function of imparting movement to the screen and so supporting the corners thereof, while movement is being imparted thereto, as to prevent any possible racking of the frame.

Each of these thrust members is identical in construction with every other, so that a detailed description of but one of them is necessary.

This thrust member comprises a metal casting having Contact plates 40 and 41 extending from each other with a 90 angle, so that when positioned in relation to the frame, oneof therplates, as 40, will engage either the front or back bar 18 orr19 of the frame, and the other plate, as 41,

will engage a side bar 16 or 17 of the frame.

Y Projecting from the angle of these plates 40 and 41 is a seat 42 adapted to fit acutout portion-28 or 30 and receive and support the'edge ofthe front and side bars of the frame at the corner., in connection with which the thrust member is used. The seat 49 is recessed as shown, to provide a suitable housing for a downwardly presented anti-friction bearing member 43.

Adjacent each of the thrust members co-operating with each unit is a bracket 44r secured to the main frame 10. This bracket is provided with a bearing 45 with which the anti-friction bearing member 43 of the thrust members cooperates.

The bearing member 45 serves to support the adjacent thrust member, and therethrough, one corner of the screen unit, while at the same time permitting free movement of said unit.

Mounted in a suitable bearing in the bracket 44is a rotatable member, as the gear 46, carrying a crank pin 47, located at a short radius of said gear, and engaging a bearing 48 in an arm 49 forming a part of the thrust member. The cutout portions 29 are provided to aiford'proper clearance between the frame of the unit and the bearing 45.

In the embodiment of the invention shown yin the'acccmpanying drawings, each of the brackets 44m-operating with a thrust member of each unit is in vertical alinement with a bracket cooperating with each of the other superimposed screen l units, andthe :gears: 46 carrie'd by e'a'chf'set of vertically alined bracketshave their axes in vertical alinement. Consequently, there are four sets of verticalflyalin'ed gears 46, thelgears of each set receiving power` through thesame shaft, andtheshafts co-operating with allof the sets of vertically alinedge'ars being driven through a mechanism receiving its vpower from asingle source. This' ensures-absolute accuracy in the timing, not only of the operationlof a-llof the gears 46: operative uponV each'unit, but of all of the-other gears operative upon the other units.

It `vis-essentialthat the crank pins47, upon the gears 46 operative upon the thrust members -cooperating with any unit, be set upon the same radius, and that all of the thrust members 'shall have theA samemovement. The crankpins 47 of one-unit maybe set upon a different radius from the crank pins of' another unit,vbutv all of the crank pins of each unit, as stated, must-be set the same. This'relieves the frame' of the screen'unitl from substantially allstrains due to the application of kpower thereto by the vactuating means therefor.

The power dshafts actuating the'gears-46 ofv each set -are shownat- 50, 51, 52 and-'53', the shaft 50 being provided with gears 54, 'theshaft 51 being provided with gears 55, the shaft52 being provided with gears 56and thershaftl 53 being 105;!

provided wiihgears 57. The gears 54,' 55, 56 and 57 respectively mesh withagear-46.

Eachlof the shafts50'to `53`carries a bevel gear, these gears'being shown at 58, 59, 60 and 615. rThe gears 58 and 59 are'enmeshed with bevel 624a'nd-63V carried by a shaft 64; The gears 60 andf61 are enmeshed with gears 65 and 66 carried by a'shaft 67. The shafts 64 and'67'each carryl a bevel gear SSL-'69, which in turn are enmeshed with bevel gears 70 and 7l upon ay main power 115,- shaft 72, which may be driven from anydesired source of power, not shown.

Theshaft 72 is driven at a speedto impart a high speed of"v rotation to the various gears 46. Good results -have'been secured by actuating the 120i screen units *atl the rate of four hundred or more cyclesper minute.

Discharging into the uppermost screen unit 11 is a feed hopper '73, having an outlet '74`of a width which will permit a free movement of :the screen-A 11. This hopper continuously! discharges cork granules orparticles upon the mesh 23 of the screen unit 11 adjacent the back bar 1'9fof the frame of this unit.

The lowermost screen unit 15 is provided with 130 an offtake pipe 75 through which dust and grit maybe withdrawn in any desired manner, as by a suitable suction device. This pipe 75 is the only outlet for the collecting and discharging hopper of this unit.

The lay-out of the gearingabove described-is such that the 'gears 46 all rotate inthe same direction andlat the same'speed. The gearing arrangement is shown4 in the drawings, and need therefore ynot be described in detail.

The operation of 'thehe'rein Vdescribed cork sifter is substantially as follows In assembling-the sifter of the invention, the various actuating and thrust members are first completely assembled in relation tov the main 145 frame 10 and each other, and the screenzunit' frames are merely ttedto the'rvarious thrustl members without being connected therewith.

It willbe noted that the discharge 74 of the hopper '73 -is adjacent the'back bar 19 ofthe 150- uppermost screen unit l1, slightly forwardly of the hopper 26. An adequate supply of granular or other material is stored in. the hopper 73, this material being free to gravitate through the outlet 74 until this outlet is clogged by the accumulation of the material upon the screen 23 of the unit 11. In this manner the supply of granular or other material delivered to this screen is controlled by the screening action, the delivery of this material being continuous as required.

When power is applied to the shaft 72, all of the shafts 50, 5l, 52 and 53 and the gears 46 carried thereby respectively are simultaneously rotated at the same speed and in the same direction.

The resultant short circular movement of the screen causes a violent agitation of the granular or other matter upon the screen proper 23, so that the smaller particles fall through the mesh of the screen and the larger particles remain thereon.

The inclination of the mesh 23 will cause the light cork particles to gradually work toward the discharge outlet 24, there being no tendency of this matter to move by gravity along the screen.

The bulk of the rejected matter will pass through the screen close to the point of discharge of the bulk of the matter upon the mesh, although with the high speed of operation of the machine, there `will be a progressive separation of the different 'stantially the same manner as the granular mass is discharged upon the screen of the uppermost unit 1l. There is a tendency of the matter delivered upon the bottom plate to collect and accumulate upon the bottom plate Vadjacent the discharge hopper, but the increased capacity of the chamber between same and the wire mesh permits this without clogging the machine.

This condition is repeated throughout the suoceeding lower units until ultimately the smallest usable particles are separated from the dust and grit, and the latter are discharged through the outlet 7s of the lowermost unit.

The graded granules or particles, passing through the discharge opening 24 of a unit, will slide along the bottom of the discharge chute 35 of that unit and pass by gravity through the conduit portion 36 movable with said chute, the flexible conduit portion 33 and the fixed conduit portion 36a to the collecting receptacle 37. The exible conduit section 38 iste permit the free movement of the movable conduit section 36 with the discharge chute and the sifter unit while directing the particles to the fixed conduit sections 36a and preventing the escape of such particles, either as a result of air currents, er as a result of the impetus given to some of these particles as a result of the rapid movements of the movable conduit section 36.

With this rotation of said gears 46, the thrust members actuated thereby respectively will each be actuated to impart or permit both longitudinal and lateral movement to the screen unit with which they co-operate. The operation of each member will differ from that of every other member, and there will be not only a reversal in the direction of movement of the screen unit during each revolution of the gear, but there will be a constantly changing longitudinal and lateral speed of the unit.

For convenience of description, the complete cycle of operations will be divided into four stages, each requiring of movement of the cranks 47 carried by the gears 46.

During the first stage, the thrust member actuated from the shaft 50 will be actuated to advance the contact plate 40 thereof to impart a longitudinal thrust to said unit, and the contact plate 41 to impart a lateral thrust thereto. There will be a progressively increasing speed in the longitudinal movement of the unit during this stage, and a progressively decreasing speed in its lateral movement.

During this stage, the thrust member actuated from the shaft 5l will be so actuated as to cause the contact plate 40 thereof to recede with the same speed variations as are present in the longitudinal movement of the screen unit, and the contact plate 4l to advance and impart lateral movement to the screen with the same speed variations therein as result from the movements of the thrust member actuated from the shaft 50.

The thrust member actuated from the shaft 52, during this stage, will be actuated so as to advance the contact plate 40 carried thereby to impart longitudinal movement to the screen in the same manner as the contact plate 40 of the thrust member actuated from the shaft 50. The contact plate Ail of this thrust member, however, will recede laterally so as to permit lateral movement of the screen unit.

The thrust member actuated from the shaft 53 will be actuated so as to cause both plates 40 and 4l thereof to merely recede longitudinally and laterally from the screen unit, and permit both longitudinal and lateral movement thereof.

The movement of each of the thrust members is the same as that of every other, so that during this movement of the screen unit, and in fact of other movements thereof, it will be supported by, and firmly held between, the various thrust units. The contact plates 40 and 4l of each thrust member, as stated, will reinforce the frame of the screen unit about the point of the application of power thereto by said thrust members.

During the second stage of the cycle, the plates 40 of the thrust member actuated from the shaft 5G will continue to advance and impart longi- Vtudinal movement to the screen unit, and the plate 4.0 of the thrust member actuated from the shaft 5l will continue to recede, both plates 40 having a progressively decreasing rate of speed. The plates 41 of both of these members, however, will recede and cease to impart any lateral movement to the screen unit. The plate 40 of 1.35 the thrust member actuated from the shaft 52 will continue to advance in the same manner as the plate 40 of the member actuated from the shaft 50, and the plate 4.0 actuated from the shaft 53 will continue to recede in the same manner 140 as the plate 40 actuated from the shaft 5l. The plates 4l, however, of the thrust members actuated from both the shafts 52 and 53 will advance with a progressively increasing speed, thus reversing the lateral movement of the screen M5 unit.

During the third stage, the longitudinal direction of movement of the screen unit will be reversed, but the lateral movement will continue throughout this stage the same as during the i5@ i thrust member actuated from the shaft 51 will have the same operative effect as the thrust member-"actuated fromthe shaft 52 duringthe first stage. The thrust members actuated by the shafts and 5?. will have the same operative eiects asv the thrust members actuated by the` shafts 53 and 51 respectively during the first stage.

During the fourth or iinal stage of the cycle, thelongitudinal movement of the screen unit will continue as during the third stage, but the lateral movement will be reversed. During this stage, the operations of the thrust member actuated from theV shaft 53 will be the same as the operations of thethrust member actuated from the shaft 50 during the second stage, and vice versa, and theoperations of the thrust member actuated from the shaft 5l will be the same as those of the thrust member actuated from the shaft 52 during the second stage, and vice versa.

The terms-advance and recede, as herein used, refer to the movements lof the contact platesl or 41 in relation to the position of theV screen at the moment.

The above operation is described at considerable length'merely to emphasize the action of theV various thrust members in relation to the frame of the screen unit. It will be noted that there is a constant shifting-of the pcintof application of power to this Yframe, and that the ar-l rangement of the contact plates 40 and 41 issuch asfto impartrigidity not only to the portion of` theframe against which thethrust occurs, but

upon bothV sides of the angle adjacent thereto.-v

The actuation of each of the superimposed.

screen units will be the 'same as that above described, although by changing the location of the crank pin 47 upon any gear 46, the timing inthe reversal in. the direction of movement, and the changes of the speed of movement may be'varied as to the diiferent units. This, however,v is merely amatter'of choice and not essential to the machine.

The advancing and receding of the diiferent thrust members in the manner described, not only imparts movement to the screen unit, but

avoids any-resistance of any part of the actuating mechanismY to this movement. Furthermore, the moving inertia of the Vscreen unit is so controlled by the thrust members that'the frequent reversal of .thedirection of movement of the screen unit cannot result inthe development of any looseness of parts and racking of this structure.

Itis obvious that the various sizes of usable material are completely segregated, by providing separate receptacles'into which the output of ther machine as a wholeis delivered.

While vI have referred to the dust and grit or as new. and desire to have protected by Letters Patent, isz- 1. A cork sifter embodying therein the combination with a sifter unit, comprising. a rectangular frame having .thereina screen, an imperfrate bottom plate beneath said screen and spaced'.

therefrom, and discharge means communicating.

respectively with the space above said. screen and above-said imperforate bottom plate, of a thrust member adjacent each corner of said. frame includingv therein contact platesextending from each other at an angle to engage said. frame about the corner thereof, a seat within the angle of said plates supporting said frame, a fixed bracket adjacent each of said thrust members, (zo-operating bearings carried by said thrust members and said brackets respectively, a rotatable member mounted upon each of saidbrackets, operative connections between said rotatable member and the thrust member associated therewith, and means common to therotatable mem.- bers associated with said unit for imparting simi lar, simultaneous movement thereto.

2. A cork sifter embodying therein the combination with a sifter unit, comprising a frame havingffront, back and side bars, a screen supported within said frame, said screen.. being pitched toward said front bar, saidfront bar having an opening therethrough above said. screen, a discharge chute communicating with said opening, an oi'ftake duct comprising a section carried by and movable with said chute, and

a fixed section, an imperforate bottom platecarsaid thrust members, co-operating bearings carried by said thrust members and said brackets respectively, a rotatable member mounted upon each of said brackets, operative connections .between said rotatable member and the thrust member associated therewith, and means common. to the rotatable members associated with said. unit for impartingsimilar, simultaneous movement thereto.

3; A cork sifter embodying therein the vcombinationwith a sifterunit, comprising a frame having front, backand side bars, a screen supported within said frame, said screen being pitched toward said front bar, said front bar having an opening therethrough above said screen, adischarge chute communicating with said opening, an offtake duct comprising a sectioncarried by and movable with said chute, a fixed section, and a exible section connecting said other conduit sections, an imperforate bottom'plate carried by `said'iramebeneath said screen'. and' spaced therefrom, and discharge meanscommunicating with the space aboves'aid' imperforate bottom plate, of a'plurality of thrust members operatively engaging the base of said frame, supporting means for said frame carried by said thrust members respectively, a fixed bracket adjacent each of said thrust members, co-operating bearings carried by said thrust members and said brackets respectively, a rotatable member mounted upon each of said brackets, operative connections between said rotatable member and the thrust member associated therewith, and means common to the rotatable members associated with said unit for imparting similar, simultaneous movement thereto.

4. A cork sifter embodying therein the combination with a sifter unit, comprising'a frame having front, back and side bars, a screen supported within said frame, said screen being pitched toward said front bar, said front bar having an opening therethrough above said i screen, a discharge chute communicating with said opening, an oitake duct comprising a section carried by and movable with said chute, and a fixed section, an imperforate bottom plate carried by said frame beneath said screen and i spaced therefrom, said bottom plate being spaced by said thrust members and said brackets respectively, a rotatable member mounted upon each of said brackets, operative connections between said rotatable member and the thrust member associated therewith, and means common to the rotatable members associated with said unit for imparting similar, simultaneous movement thereto.

5. A cork sifter embodying therein the combination with a sifter unit, comprising a rectangular frame having therein a screen, an imperforate bottom plate beneath said screen and spaced therefrom, and discharge means communicating respectively with the space above said screen and above said imperforate bottom `plate, of a thrust member adjacent each corner of said frame including therein contact plates extending from each other at an angle to engage said frame about the corner thereof, a seat within the angle of said plates supporting said frame, a downwardly presented bearing carried by said seat, a fixed bracket adjacent each of said thrust members, said bracket having a bearing co-operating with the bearing upon said support, a gear rotatably mounted upon said d bracket, a crank pin uponV said gear, an arm bearing upon said crank pin carried by said thrust member, and means common to the gears carried by the brackets associated with said unit for imparting similar, simultaneous movement ,to said gears, said crank pins being set upon the same radius of each of said gears.

6. A cork sifter embodying therein a sifter unit having a rectangular frame, thrust members operatively engaging diametrically opposite cor- `ners of said frame, supporting means for said frame carried by said thrust members respectively, a fixed bracket adjacent each of said'thrust members, co-operating bearing members carried by said thrust members and said brackets respectively, a rotatable member mounted upon each Larmes of saidA brackets, operative connections between said rotatable member and the thrust member associated therewith, and means common to the rotatable members associated with each unit for imparting similar, simultaneous movement thereto. Y

7. A cork sifter embodying therein a sifter unit having a rectangular frame, a thrust member adjacent each corner of said frame including there* in contact plates extending from each other at an angle to engage said frame about the corner thereof, a seat within the angle of said plates supporting said frame, a fixed bracket adjacent each of said thrust members, cooperating bearings carried by said thrust members and said brackets respectively, a rotatable-member mount- Ved upon each of said brackets, operative connections between said rotatable member and the thrust member associated therewith, and means common to the rotatable members associated with said unit for imparting similar, simultaneous movement thereto.

8. A cork sifter embodying therein a sifter unit having a rectangular frame, a thrust member adjacent each corner of said frame including therein contact plates extending from each other at an angle to engage said frame about the corner thereof, a seat within the angle of said plates supporting said frame, a downwardly presented bearing carried by said seat, a xed bracket adjacent each of said thrust members, said bracket having a bearing co-operating with the bearing upon said support, a gear rotatably mounted upon said bracket, a crank pin upon said gear, an arm bearing upon said crank pin carried by said thrust member, and means common to 'the gears carried by the brackets associated with said unit for imparting similar, simultaneous movement to said gears, said crank pins being set upon the same radius of each of said gears.

9. A cork sifter embodying therein a sifter unit having a rectangular frame, a thrust member adjacent each corner of said frame, including therein contact plates extending from each other at an angle to engage said frame about the corner thereof, a seat within the angle of the plates of each thrust member supporting said frame, a downwardly presented bearing carried by said seat, a fixed bracket adjacent each of said thrust members, each bracket having a bearing cooperating with the bearing upon said support, a gear rotatably mounted upon each bracket, a crank pin upon said gear, an arm bearing upon said crank pin carried by the co-operating thrust member, said gears being arranged in four sets having their axes vertically alined, vertical shafts carrying the gears of each set, and means simultaneously driving all of said shafts so as to rotate all of said gears in the same direction and at the same speed, said crank pins co-operating with each unit being set upon the same radius of each of the gears carrying same.

JOHN D. ELDER. 

